“I began to see some of the high profile, very dramatic experiments in social psychology of the 1950s and 60s, as what they were – metaphors. We invest them with a truth and authority that often goes way beyond what we’ve demonstrated in the lab” says Gina Perry.

The particular experiments she is taking a fresh look at in her book, Behind the Shock Machine, are the Milgram experiments, conducted at Yale University in 1963, which suggested that 65% of people would give fatal electric shocks to complete strangers if asked to do so by an authority figure. These experiments have been used to ‘explain’ the behaviour of Nazis in the holocaust. Stanley Milgram’s findings are shocking, but are they valid? That is the central question Perry seeks to address.